Trenches for directing storm water to subterranean basins are commonly found in paved surfaces such as driveways and parking lots, and are typically found across vehicular entrances and interior surfaces of the pavement. To allow for vehicular travel over the trench, these trenches are typically covered by substantial grates or grating systems and assemblies, portions of which are embedded into the surrounding pavement.
Typical trench grate assemblies include two parts: a frame section and a grate section. The frame section comprises a metal component that is positioned over a ledge formed in the pavement along the sides of the trench and is sized and dimensioned to receive the grate. A portion of the frame is typically formed to be received in the pavement surrounding the trench, to anchor the frame in position. The grate provides a surface that can support a vehicle traversing the trench, but includes apertures that allow water and other fluids to flow into the underlying trench. The grate is typically constructed of individual pieces that are laid end to end along the trench to provide an overall grating system of a selected length. Each frame piece typically includes apertures sized and dimensioned to receive threaded fasteners, and the frame pieces are coupled to the frame using a fastener such as a threaded coupling device that extend through the apertures formed in the frame, and into the concrete ledge.
Although these prior art devices provide suitable drainage trench structures, the need for a ledge for mounting the frame limits the size, and particularly the width, of the drainage system that is provided by the frame construction. Additionally, because a corresponding ledge is required in the grate, a significant amount of material is devoted to mounting the drainage system, rather than to providing a useable drainage structure, thereby increasing the cost of the overall trench system. Furthermore, because the frame rests on a concrete ledge, the apertures for receiving fasteners to join the frame and grate members together necessarily rest on the ledge and can become filled with dirt or debris, making it difficult or impossible to properly tighten the fasteners. In addition, prior art trench frames have relatively limited framing for retaining the frame in the concrete, and therefore can be subject to damage when used heavily or subjected to substantial weights. The present invention addresses these problems.